The photographic film that is in the most widespread use today is 35-mm film (system 135) as provided for by Japanese Industrial Standards (JIS) and International Organization of Standardization (IOS).
U.S. Pat. No. 5,049,908 describes a photographic camera and a film therefor, with the film being of a 35-mm size devoid of sprocket holes of the size used in present 35-mm films and having an effective image area of about 30 mm across the film, thereby providing an increased effective usable film area.
More specifically, ignoring dimensional tolerances, present 35-mm films for use in general photography have a width of 35 mm between opposite longitudinal edges and include a series of film-transport perforations or sprocket holes defined along the opposite longitudinal edges of the film. The film-transport perforations are spaced 25 mm across the film and have a pitch of 4.75 mm. Frames on such a present 35-mm film are of a rectangular shape having a width of 25 mm across the film and a length of 36 mm along the film. The frames have a pitch of 38 mm, which is eight times larger than the pitch of the film-transport perforations.
As described in U.S. Pat. No. 5,049,908, some modern photographic film cameras are electronically controlled to provide motor-driven operation with high accuracy, and it has been experimentally confirmed that the film can be transported quite accurately without requiring the large sprocket wheels and film perforations that are found in most present cameras and films. In the system described in U.S. Pat. No. 5,049,908, the film-transport perforations are not present in the 35-mm photographic film, thereby increasing the available frame width across the film up to the regions where such film-transport perforations were located. The proposed film thus has an increased effective image area for improved image quality. This patent describes four sizes that are available for frames that can be exposed on a 35-mm film free of film-transport perforations.
According to one size, a frame that can be exposed in an effective image area of the 35-mm film has a width of 30 mm across the film and a length of 40 mm along the film. The frames of such a size have a pitch of 42.0 mm, for example. The frame size and pitch are selected to match specifications of the present television broadcasting system, for example, the NTSC system. Therefore, the frames have an aspect ratio of 3:4.
Another frame size described in that patent is based on High-Definition Television (HDTV) specifications, in which frames have a width of 30 mm and a length of 53.3 mm and a pitch of 57.75 mm, for example. The aspect ratio of the frames having that size is 9:16.
The above-mentioned frame sizes are full-frame sizes, and the other two frame sizes are half-frame sizes. According to one of the half-frame sizes, frames have a width of 30 mm and a length of 22.5 mm and a pitch of 26.2 mm, for example, to match present television broadcasting system specifications. According to the other half-frame size, frames have a width of 30 mm and a length of 16.9 mm and a pitch of 21.0 mm, for example, to match HDTV specifications.
Film with the above four frame formats is stored in the same film cartridge as presently available 35-mm film.
Because the frames in either of the above frame formats have a width of 30 mm, there are unexposed areas of about 2.5 mm between the frames and along the opposite longitudinal edges of the film. These unexposed areas may be used to keep the film flat, control the film, and write and read data when taking pictures.
The proposed camera may be relatively small and lightweight, because it does not require film-transport sprocket wheels.
Films that are actually collected in processing laboratories are processed either simultaneously in a batch or individually. In a simultaneous batch process, several thousand films are processed per hour at a high rate to realize economics of scale for reducing the printing cost. Specifically, a plurality of exposed films are collected in the processing laboratory and are spliced end to end to form a long, continuous film strip, which is then stored in a film magazine and subsequently processed.
If the films that are spliced into the continuous strip contain frames exposed in different frame formats, such as disclosed in U.S. Pat. No. 5,049,908, then the long single film stored in the film magazine contains different frame sizes, thereby making printing a problem.
U.S. Pat. Nos. 4,384,774 and 5,066,971 propose cameras capable of switching between half and full frame sizes at the time the film is exposed. When film exposed using these proposed cameras is spliced into a long, single, film strip for simultaneous batch processing, the continuous film strip also contains different frame sizes.
The processing laboratories are therefore required to form notches indicative of frame centers for automatically printing spliced films with different frame sizes after they are developed. For example, as disclosed in U.S. Pat. No. 4,557,591, a human operator manually notches a side edge of a spliced film and, hence, the notches are required to control the feed of the film. With the disclosed process, it is impossible to process several thousand films per hour, however, the cost of processing exposed film is relatively high. As a consequence, films with different frame sizes may not be accepted by processing laboratories in Japan.
Many processing laboratories all over the world also do not accept films with frames exposed in half size because they do not want different frame sizes to be contained in a single spliced film that is stored in a single film magazine for subsequent processing and printing. This problem arises because the different frame sizes can be recognized only after the film has been developed. One solution would be to apply marking seals to exposed films so that the films of different frame sizes thereof can be distinguished and sorted out for individual processing and printing. Nevertheless, use of marking seals would not essentially solve the problem, because it would be difficult to supply such marking seals consistently over a number of years.